Phonograph attachment



R. W. MORRISON.

PHONOGRAPH ATTACHMENT. APPLICATION FILED APR. 8. 1919.

Patented June 22, 1920.

anmmtoz "UNITED STATES "PATENT OFFICE.

RALPH W. 'MORRISON, OF OMAHA, NEBIRASILA, ASSIGNOR TO CATHEDRAL PHONO GRAPH COMPANY, OMAHA, NEBRASKA, A CORPORATION 0F NEBRASKA.

PHONOGRAPH ATTACHMENT.

Specification of Letters Patent. Patented J 11119 22, 1920,-

Application filed April 8, 1919. Serial No. 286,559.

To all whom it may concern:

Be it known that I, RALPH W. MORRISON, a citizen of the United States, residin at Omaha, in the county of Douglas and tate of Nebraska, have invented certain new and useful Improvements in Phonograph Attachments, of which the following is a speclfication.

This invention relates to a phonograph attachment, and has for its object to provide means to normally maintain the stylus within the spiral groove of the disk during. operation orrotation of the disk, this being of great utility in instances where the disk is disposed inclinedly.

The invention consists of the novel construction, combination and arrangement of parts as described herein and claimed, and

as illustrated in the accompanying drawing,

wherein,-

Figure 1 1s a 'VlBW 1n side elevation of certain operating parts of a phonograph withthe attachment applied. Fig. 2 is' a view similar to that shown in Fig. 1, being.

a modified form'of the invention. Figs. 3 and 4 are broken away, sectional views on an enlarged scale illustrating forms in cross section of spiral grooves of disks.

Referring now to the drawing for a more particular description, the invention is illustrated in connection with certain well known mediate its-*ends by means of a cord14' which is connected with'the diaphragmof the sound box, wherebythe stylus-arm will be supported in approximately a horizontal position with its stylus lli engagingin the groove of the disk 16. a

It is well known that certain disk-records 17, as shown inFig. 3 are'employed which are providedwith grooves 18 of inverted V- shape in cross-section; also that other diskrecords as shown in Figgl are employed, these belng provlded wlthgrooves 20 which,

in cross-section have a uniform curvature; also, for engaging 1n the grooves 20 a stylus 15 is used which has a curvature conforming to the shape, in cross-section, of said grooves 20, with the result in the use of the latter that the element 15, during operation, occasionally will not remain in the groove but will be shifted transversely to enter an adjacent groove, especially if the diskrecord 16 is disposed inclinedly.

The object of the invention, therefore, is to provide means for causing a constant pressure of the stylus against the disk for maintaining it within the groove during the revolublemovement of the disk 16 regardless of the inclination of said disk, and for this purpose I employ an electromagnet 21 which, in Fig. 1, is disposed 'below the stylus and below the disk, said electromagnet being supported by any suitable means and to be electrically energized by any suitable means, an electric battery being shown for this purpose, the stylus-arm shown in said Fig. 1 having a terminal metallic part a and having. an insulated part 6 intermediate its meta'llic part a and it's pivotal mounting 8.

In Fig. 2 is shown a modified form of the invention, a stylus-arm 7 being employed having the form of a rock-lever, said arm opposite to the stylus 15, said metallic part being disposed below and adjacent to an electromagnet 21' energized by the electric battery 22 or other suitable electrical supply, and having an insulating part at between the metallic part c and the pivotal mount In operation, the electromagnet will cause a pressure of the stylus 15 against the disk: .16 and thereby will normally maintain the stylus within a groove 20. The use of the attachment will be appreciated since the disk 16 occasionally may be disposed inclinedly,

thereby causing the stylus to be shifted transversely to an adjacent groove. The device-is part cularlyof advantage in instances where the grooves are shallow and are of curved form 1n cross-section, the stylus having a.convexed -surface conforming to the curvature of. the groove, since it is dependable for the purpose described regardless of the degree of'inclination of the disk.

I claim:

1, In combination with a pivotally mounted tylus-arm and revoluble disk of a phonograph, an electromagnet disposed within operative proximity to the stylus-arm for normally causing a pressure of the stylus against said disk.

2. An attachment for phonographs, comprising, in combination With a revolu ble, spirally grooved disk, at pivotally mounted stylus-arm having an insulating part and having a metallic part provided with a stylus, an electromagnet disposed within operative proximity to the metallic part of 10 the stylus-arm for causing a pressure of the stylus Within the groove of the disk.

In testimony whereof I have a'flixed my signature in presence of two Witnesses.

RALPH W. MORRISON. Witnesses:

HIRAM A. STURGES, ARTHUR H. STURGES. 

